Chong Lou
StarParis polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. / Paris polyphylla Smith var. chinensis (Franch.) Hara
Traditionally used for
- Colds & fever
- Nerves & recovery
Cautions & contraindications
- Pregnancy
- Liver conditions
- Toxic — professional use only
☯ TCM Properties
Clears Heat and Resolves Toxicity; Reduces Swelling and Alleviates Pain; Settles Fright and Calms Convulsions
Traditional Chinese Uses
Chong Lou (paris rhizome, herb paris) is a cold, bitter, slightly toxic herb used in Chinese medicine to clear Heat toxin, reduce swelling, calm Wind, and stop convulsions. It is a potent herb for toxic swellings, venomous snake bites, carbuncles, and abscesses, and its Wind-calming action extends to febrile convulsions and seizures from extreme Heat entering the body's deepest levels. Due to its toxicity, it requires professional prescription and careful dosing.
Relationships
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Botanical Description
Paris polyphylla is a rhizomatous perennial herb in the family Melanthiaceae, native to the Himalayan region and montane forests of southwestern China. It produces a single erect, unbranched stem 30-100 cm tall bearing a solitary whorl of four to nine ovate-lanceolate leaves at its apex. From the centre of this whorl a single terminal flower arises, with narrow green outer tepals and thread-like yellowish inner tepals, surrounding a dark purple ovary. The thick, knotty, creeping rhizome is yellowish-brown externally and pale internally, with prominent stem scars. Fruits are fleshy capsules releasing red-coated seeds. The variety yunnanensis is the principal source of medicinal material harvested in autumn.
Active Constituents
Polyphyllin I (Paris saponin I)
Pennogenin-type steroidal saponinConcentration: one of four saponins assayed by the Chinese Pharmacopoeia, which requires the combined content of polyphyllins I, II, VI and VII to be not less than 0.60% of the dried rhizome
The best-studied cytotoxic constituent, driving apoptosis in tumour cells through reactive oxygen species stress and death-receptor signalling converging on caspase activation. The same mechanism operates on normal hepatocytes: in HL-7702 human liver cells polyphyllin I was among the two most potent of the four saponins tested, so its anticancer and hepatotoxic actions cannot be separated.
Polyphyllin II (Paris saponin II)
Pennogenin-type steroidal saponinConcentration: assayed jointly with polyphyllins I, VI and VII to a combined minimum of 0.60% of the dried rhizome
Cytotoxic to tumour lines and, dose- and time-dependently, apoptotic to normal hepatocytes; it ranked second most toxic of the four saponins in HepaRG cells.
Polyphyllin VI (Paris saponin VI)
Diosgenin-type steroidal saponinConcentration: assayed jointly with polyphyllins I, II and VII to a combined minimum of 0.60% of the dried rhizome
The least hepatotoxic of the four pharmacopoeial saponins in both HL-7702 and HepaRG hepatocyte models, distinguished from the pennogenin-type saponins by the absence of the C-17 hydroxyl.
Polyphyllin VII (Paris saponin VII)
Pennogenin-type steroidal saponinConcentration: assayed jointly with polyphyllins I, II and VI to a combined minimum of 0.60% of the dried rhizome
The most cytotoxic of the four saponins to HepaRG hepatocytes. Like the others it raises reactive oxygen species, collapses mitochondrial membrane potential, releases cytochrome c and upregulates Bax and p53.
⚠ Drug Interactions
Hepatotoxic drugs (e.g. paracetamol/acetaminophen, methotrexate, isoniazid, azole antifungals)
All four pharmacopoeial Paris saponins are directly toxic to normal human hepatocytes in vitro, inducing apoptosis dose- and time-dependently through reactive oxygen species and death-receptor pathways (Wang et al., Cells 2019). In a 45-day subchronic rat feeding study, Rhizoma Paridis saponins caused slight liver injury with elevated serum AST, ALT, alkaline phosphatase and gamma-glutamyl transpeptidase alongside histopathological change and markers of oxidative stress. The authors of the in vitro work state plainly that hepatocellular toxicity should be considered during clinical application of this drug.
Clinical note: Avoid combining Chong Lou with hepatotoxic drugs, and avoid it altogether in established liver disease. Keep courses short, stay within pharmacopoeial dosing, and check liver function if use extends beyond a few weeks or if anorexia, nausea or jaundice develops.
Proprietary Chinese medicines containing Rhizoma Paridis (e.g. Yunnan Baiyao, Gongxuening capsules)
Rhizoma Paridis is a constituent of the Baiyao series and is the main raw material of Gongxuening capsules, used for abnormal uterine bleeding. A patient taking a decoction containing Chong Lou alongside either proprietary product receives the same saponins twice, and the dose-limiting toxicities of those saponins are hepatic and gastrointestinal.
Clinical note: Take a specific history for Yunnan Baiyao and Gongxuening before prescribing Chong Lou, and count the proprietary product towards the total saponin exposure rather than treating it as unrelated.
NSAIDs and other gastric irritants (e.g. ibuprofen, aspirin, corticosteroids)
Rhizoma Paridis saponins are direct gastric irritants; nausea, vomiting and diarrhoea are the reported side effects that prompted work on curcumin as a mitigating co-treatment, and high doses of the steroidal saponins have been associated with small-intestinal bleeding. Adding an NSAID or corticosteroid compounds the mucosal insult.
Clinical note: Administer after food, keep to the low end of the dose range, and reconsider the herb entirely in patients on regular NSAIDs, in peptic ulcer disease, or where gastrointestinal bleeding would be dangerous.
Warfarin and other anticoagulants or antiplatelets
Rhizoma Paridis is the haemostatic principal of Gongxuening and a component of Yunnan Baiyao, so a pharmacodynamic opposition to anticoagulants is plausible; no human interaction study supports or refutes it. Pulling in the other direction, high-dose saponins have been linked to intestinal bleeding. Neither effect has been quantified in anticoagulated patients.
Clinical note: If the combination cannot be avoided, monitor INR or the relevant coagulation parameter more frequently after starting or stopping the herb, and warn the patient to report any bleeding.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–9 g | — | — | — | ChP 2025.. Corrected from a generic 6-15g decoction filler value generated from tcm_category. |
| topical | Appropriate amount | — | — | — | ChP 2025. 外用适量，研末调敷。 |
Evidence Tier
Moderate evidence · 3 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
2
1 verified · 1 unverified
Other / unclassified
1
1 verified · 0 unverified
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Hepatocellular Toxicity of Paris Saponins I, II, VI and VII on Two Kinds of Hepatocytes-HL-7702 and HepaRG Cells, and the Underlying Mechanisms
All four pharmacopoeial Paris saponins were cytotoxic to two normal human hepatocyte lines, inducing apoptosis dose- and time-dependently. In HL-7702 cells saponins I and VII were most potent and VI weakest; in HepaRG cells the order was VII, II, I, VI. Mechanistically the saponins raised reactive oxygen species, collapsed mitochondrial membrane potential, released cytochrome c and upregulated Bax and p53, with polyphyllin I acting through both the ROS-stress and death-receptor routes. The authors conclude that hepatocellular toxicity should be weighed whenever Rhizoma Paridis is used clinically.
Curcumin alleviated the toxic reaction of Rhizoma Paridis saponins in a 45-day subchronic toxicological assessment of rats
Forty-five-day dietary subchronic toxicity study in rats. Rhizoma Paridis saponins caused slight liver injury, with elevated serum AST, alkaline phosphatase, ALT and gamma-glutamyl transpeptidase and corresponding histopathological change, together with oxidative stress markers including reactive oxygen species, malondialdehyde and 8-hydroxy-2-deoxyguanosine. Co-administered curcumin mitigated both the hepatic injury and the gastric irritation the saponins otherwise produce. The study is the clearest in vivo evidence that repeated dosing, not merely acute overdose, damages the liver.
Paris in the spring: A review of the trade, conservation and opportunities in the shift from wild harvest to cultivation of Paris polyphylla (Trilliaceae)
Review of the trade and conservation position of Paris polyphylla. Roughly 800-1050 tonnes of rhizome are sold annually, drawn overwhelmingly from wild collection in China, India and Nepal, against a slow-growing high-altitude forest species already pressed by habitat loss, fragmentation and grazing. The authors conclude there is strong evidence for adding wild-harvested Paris polyphylla to CITES Appendix II, and note that China is the only country cultivating it at any scale. Paris polyphylla is not at present listed on any CITES Appendix; it is assessed as Vulnerable on the IUCN Red List. Practitioners should therefore source cultivated material and treat wild-collected Chong Lou as ethically and ecologically problematic.
⚠ Safety & Contraindications
- Pregnancy
- Liver conditions
- Toxic — professional use only
Contraindications
Contraindicated in pregnancy and in the weak or depleted.
Safety Warnings
- Dose-sensitive; overdose is the usual cause of reported poisonings.
- The genus is under conservation pressure from wild collection — prefer cultivated material.
⚠ Toxicity Information
Nausea, vomiting and abdominal pain; in overdose, haemolysis and cardiac disturbance.
Historical Texts
Shen Nong Ben Cao Jing
Han dynasty (compiled by the 2nd century CE)References
- Cunningham AB, Brinckmann JA, Bi Y-F, Pei S-J, Schippmann U, Luo P. Paris in the spring: A review of the trade, conservation and opportunities in the shift from wild harvest to cultivation of Paris polyphylla (Trilliaceae) . Journal of Ethnopharmacology (2018) [DOI]
- Wang W, Liu Y, Sun M, Sai N, You L, Dong X, Yin X, Ni J. Hepatocellular Toxicity of Paris Saponins I, II, VI and VII on Two Kinds of Hepatocytes-HL-7702 and HepaRG Cells, and the Underlying Mechanisms . Cells (2019) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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